Good idea here! The game works and it feels much more like a game than mine does! That said a few things I few tweaks I might recommend:
When you begin the game an enemy spawns on top of you immediately. Kinda feels off you know?
Power-ups would be a sweet addition like health packs dropping randomly or chance of dropping upon killing an object.
I thought the sprites were well done and I really like the damage state.
I see that you built this on Unity. Did you use UI Toolkit? If so, how did you manage to get the UI to scale correctly? I was having all sorts of issues with that on mine.